The present invention relates to downhole fishing and drilling operations, or retrieving obstructions to a drilling line when such a line becomes lodged or otherwise stuck in the well bore. Conventional means of downhole retrieval are dubious, and usually involve attempting to actuate the entire work string in the hope of dislodging it or removing an obstruction. Often this is unsuccessful either because the work string cannot jar loose the obstructions, or adequate motion cannot be effected in the well bore. Consequences of this failure to remove the obstruction can be failure of the well to produce at all or in part, also, older methods of removing obstructions can result in line breakage, both of which result in having to relocate the drilling operation, which necessarily involves lost time and money.
The present invention is able to attempt to actuate a lodged object in the path of the drilling path without moving the work string, which results in reduced trauma and friction and prevents work-hardening of the work string. The tool can also have various other applications, such as drilling, retrieving or driving other tools that may be attached to it, or in any application, down hole or otherwise, that may require such a jarring or oscillating action.
One objective of this invention is to provide a device capable of maintaining tensile force on a drilling work string while dislodging an object that may be interfering with the well operation.
Another objective of the invention is to provide a device that is more efficient at dislodging obstructions interfering with well operations.
Still another objective of the invention is to provide a device that can be placed into any confined space and perform a jarring action, or drive other tools that require linear input.
Other objects and advantages of this invention shall become apparent from the ensuing descriptions of the invention.
According to the present invention, the flow-activated valve assembly is a fluid-driven tool for use in various down hole drilling and fishing operations, which is activated by the introduction of fluid into an enclosed assembly, whereby fluid forces a movable portion of such assembly to slide until it engages a stationary portion, where an impact is realized, and at which time the fluid is permitted to exhaust. Upon this impact, another valve is opened to permit fluid to flow in another channel, moving the assembly in the opposite direction until it reaches a second stationary portion, at which point another impact is realized in the opposite direction. This creates a bi-directional hammering effect for each cycle of the tool, which can be utilized in various applications, either for the jarring effect, the linear motion, or a combination of both.